Dual evaporator refrigeration apparatus



June 2, 1953 F- ALS|NG I 2,640,327

DUAL EVAPORATOR REFRIGERATION APPARATUS 4 Filed July 30, 1949 2 Sheets-Sheet 1 III Evomrutor From E:

1 5/ 5! 5 h f I IBE'JELEIBI 66 73a FIGS.

INVENTOR "CARL F. ALSING ATTORNEY 2 1953 c. F. ALSING I I 2,640,327

DUALEVAPORATOR REFRIGERATION APPARATUS Filed July 30, 1949 .2 Sheets-Sheet 2 WITNESSES:

INVENTOR CARL F. ALSING ATTORNEY Patented June 2, 1953 UNITED STATES PATENT OFFICE DUAL EVAPORATOR REFRIGERATIQN APPARATUS Carl F. Alsing; Wilbraham, Mass. assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa a corporation 'of Pennsylvania Application July/30, 1949, Serial No. 107;;790

4 Glaims. 1

This invention relates to refrigeration apparatus and more especially to such-apparatus comprising tworeirigerant evaporat'ors supplied'by a common refrigerant liuuefying apparatus.

It is an object of the invention to provide a vessel' which houses portions of the temperature regulating apparatus of one of twoevaporators and also forms a refrigerant header for both evaporaters.

It is a further object of the invention to provide a temperature regulating apparatus for each of two evaporators which apparatus also starts the operation of the refrigerant supplying apparatus when either of said evapora-tors requires liquid refrigerant.

These and other objects are effected by my invention as will be apparent-from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a view in perspective-of a refrigerator cabinet adapted for use with the refrigerating apparatus. of thisinvention;

Fig. 2 is a schematic "view in perspective of the refrigerating apparatus of this invention;

3 is. a sectional view or a portion. of the temperature regulating-device of one of the evaporatorsrshown in Fig. 2.;

4 is a modification of. the refrigerating. apparatus'of this invention;

Fig. 5. is aview similar to Fig. 3 and shows the temperature regulating apparatus of one of the evaporators of Fig. :4 and Fig. '6 is aview in elevation of the apparatus shown in Fig. 5.

Referring now to Figs. 1,. 2 and 3,0f the drawings,;.the reference numeral 1-0 designates the food storage. chamber of the refrigerator. This chamher It is divided by a horizontal partition -12 into an upper compartment it. maintained atv a temperature at about 40 F. and a lower compartment It located below the partition t2 and maintained at a temperatureof-about F.

The lower compartment It is cooled by the first portion is of a refrigerant. tube 25]- which is secured to the bottom wall; the twoside walls, and top wall of the lower compartment it; A second portion 22 of the tube '20 extends upwardty and passes downwardly through a vessel 28*. The downwardly extending end oifthe portionlc is secured toethe metal side wall 26 of the upper-compartment it by a metal clip 2-8 and th'e end 38 of the tube "portion 2-2 is closed. The. tube portion '22 within the vessel 2 4 has an opening :32 il'o'caated nearItheIbase -ot the vessel N 2 and another opening 3 5 in an upper portion of the vessel 24..

An inclined tube 36 extends through the bottom of the vessel 2t and the upper end of the tube 36 is located. adjacent the opening 34' to'receive any refrigerant liquid issuing therefrom. The tube at; at its lower end, communicateswith a somewhat smaller tube 38" which is secured against the upper portion of the metal side walls and rear wall of the upper compartment H and forms a refrigerant evaporator to coolthis compartment. The upper end 3919f the tube 3 3--communioates with the upper portionof the vessel24.

A suction tube it communicates with an upper portion of the vessel E i and with a sealed casing 32. which houses a refrigerant compressor 44 and an electric motor 45' for driving the compressor it. The refrigerant vaporenters the compressor 4 1' through an inlet tube 48 and leaves the .compressor it through a. pressure tube 56 which conducts it to an air-cooled condenser .52. The condensed refrigerant liquidilows from the condenser '52 through a capillary tube 54' to' the entrance of the tube 20.

The electric motor 46 receives power through leads 56, and a thermostatic switch 58 is'interposed in one of the leads .56. A bulb' 60 is located in heat tran'sfer' relationship with" the first'por 't-ion it of the tube 2!! and contains a volatile liquid, the'vapor pressure of which is transmitted through-a tube 62 to the thermostatic switch '58. The bulb 69' "and the thermostatic switch 58 energize the motor 46 when the temperature of the first portion 18 of the tube 20 rises above a predetermined temperature and shuts off the"motor it when the temperature of'this' tube portion it rises above a second predetermined temperature which is higher than the first predetermined temperature.

Operation of first embodiment clip "-E'B and the tubeporti'ofi below the opening 34 forms a vapor actuated lift pump which draws in refrigerant liquid through the opening 32 and discharges it through the opening 34. The mixture of refrigerant liquid and vapor issuing from the opening 34 flows into the tube 36 where the refrigerant liquid tends to separate by gravity from the vapor and runs down into the tube 38 to refrigerate the same, whereas the refrigerant vapor is drawn upwardly through the suction tube 40 if the refrigerant supplying apparatus is runnmg.

The column of refrigerant liquid and vapor in the tube portion 22 between the openings 32 and 34 will also oppose the fiow of any refrigerant liquid running downwardly in the portion of the tube 22 above the opening 34 so that this downwardly running liquid is diverted through the opening 34 directly into the tube 38. The refrigerant liquid vaporized in the tube 38 returns to the vessel 24 through the upper end 39 of the tube 38. It is thereafter withdrawn through the suction tube 40.

It will be apparent from the above that if the refrigerant apparatus is operating, the lower compartment l will be cooled until its lower temperature limit is reached and that refrigerant liquid will also be supplied to tube 38 to refrigerate the upper compartment I4 if its temperature is above a certain predetermined temperature.

Description of second modification Referring now to Figs. 1, 4, 5 and 6 showing the second modification of the invention, the parts which are identical to those of the first modification are provided with the same reference numerals as those of the first modification.

Parts which are merely similar to those of the first modification are provided with the same reference numerals as those of the first modification but with the sufiix a added thereto.

In the second modification, the capillary tube 54a discharges directly into a larger tube 66 which '12 and controlled by a switch 14. The switch 14 is responsive to the pressure of a volatile liquid located in a bulb 16 which pressure is transmitted to the switch 74 through a tube 78.

The upper compartment I4 of the refrigerator is cooled by a tube 380: into which the refrigerant liquid is transferred through the opening 34 in the same manner as in the previous modification. The tube 38a is in heat transfer relationship with the bulb 76. A second bulb Ella, is located in heattransfer relationship with the tube 65. A volatile liquid in the bulb 60a actuates the switch 59 through the tube 62.

A tube |8a communicates at both ends with a lower portion of the vessel 24a. and is secured to the walls of the lower compartment IS in the same manner as the tube I8 of the first modification. The vessel 24a, the tube 56, the heater I9 and the bulb 6911 are located in the thermal insulation of the walls of the refrigerator.

Operation of second embodiment liquid to fill the vessel 24s as well as the tube 18a.

If the temperature of the tube 38a, which cools the upper or warmer compartment, exceeds a predetermined value, the switch 14 closes and energizes the heater 10. This vaporizes the refrigerant liquid in the tube 66 and the action of the vapor actuated lift pump comprising the tube 63 commences. Refrigerant liquid is forced through the opening 34 and flows into the tubes 36 and 38a.

At the same time the heater l0 warms the bulb 69a to close the switch 59 if open and actuate the refrigerant supplying apparatus, 42, 52. Refrigerant liquid is thereupon supplied to the vessel 24a and the vapor pressure in the vessel 2% is reduced. This vaporizes the refrigerant liquid in the tube 38a and cools the upper compartment it of the refrigerator.

When tube 38a is cooled to the predetermined temperature at which switch 14 opens, the heater I0 is deenergized and the pumping action of the tube 66 ceases. The refrigerant supplying apparatus 42, 52 continues to operate until tube 66 is reduced to the temperature at which switch 53 opens. Before tube .66 reaches this temperature, however, all of the refrigerant liquid in tube 38a evaporates since it now is the warmest refrigerant liquid on the suction side of the refrigerant supplying apparatus d2, 52.

When the refrigerant liquid in the evaporator 38a has evaporated, tube 69 will assume the same temperature as the tube 18a since tube 66 is located in the thermal insulation of the cabinet and is subjected to the same suction pressure as the tube 811. Tube 68 together with tube We is now cooled until the bulb 68a opens the switch 58.

Tubes 66 and we tend to be at the same temperature even when the refrigeratin apparatus d2, 52 is inactive because both are subjected to the same pressure. If tubes 39 and l8a warm up to the temperature at which switch 58 closes before the tube 33a warms up to the temperature at which switch it closes, the refrigerant supplying apparatus 52, 52 will be energized but will supply only the tubes 18a and 6b.

While in this modification the refrigerant liquid is conducted directly to the vessel 24a, this is not essential since it might also be conducted directly to the tube we as in the first modification of the invention. It will be apparent from the above that in each of the modifications, the vessel 24 and 24a forms a refrigerant header for both the tubes which cool the upper compartment and the lower compartment as well as for the vapor actuated lift pump. It will be further apparent that in the second modification, the refrigerating apparatus will be actuated when either the upper compartment or the lower compartment of the refrigerator requires refrigeration and the compartment requiring refrigeration will be cooled substantially to the exclusion of the other compartment.

While I have shown the invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What I claim is:

1. In refrigerating apparatus, the combination of a vessel adapted and arranged to store refrigerant liquid, refrigerant vapor compressing and condensing apparatus adapted to supply refrigerant liquid to said vessel, a first evaporator, a first conduit connected at one end tosaid vessel at a first portion thereof spaced. from the bottom of the vessel, said first conduit being connected at its other end to said first evaporator, said first conduit conducting refrigerant liquid from said vessel to said first evaporator, a second evaporator, a. second conduit connected at one end to said vessel at a second portion there of located at an elevation above that of said first portion, said second conduit being connected at its other end to said second evaporator, and a pump adapted to pump refrigerant liquid from an area of said vessel located below said first portion, said pump discharging said liquid into said second conduit.

2. The refrigerating apparatus defined in claim 1 including means for actuating said pump in response to a predetermined high temperature of said second evaporator.

3. The refrigerating apparatus defined in claim 1 including temperature-responsive means for controlling said compressing and condensing apparatus to maintain the temperature of said first evaporator substantially constant and to actuate said pump in response to the temperature of said second evaporator to keep the temperature of the latter substantially constant.

4. In refrigerating apparatus, the combination of a vessel adapted and arranged to store refrigerant liquid, refrigerant vapor compressing and condensing apparatus adapted to supply refrigerant liquid tosaid vessel and withdraw refrigerant vapor therefrom, a first evaporator, a first conduit means connected at one end to said vessel at a first portion thereof spaced from the bottom of the vessel, said conduit means being adapted and arranged to conduct refrigerant liquid from said vessel to said first evaporator and refrigerant vapor from said first evaporator to said vessel, a second evaporator, second conduit means connected at one end to said vessel at a second portion thereof, said second portion being at a higher elevation than said first portion, said second conduit means being adapted to: conduct refrigerant liquid from said vessel to said second evaporato and refrigerant vapor from said second evaporator to said vessel, a vapor actuated lift pump adapted to pump refrigerant liquid from a. portion of said vessel below said first area into said second conduit means, a heater for operating said pump, a first control means responsive to the temperature of said evaporator for actuating said pump when the temperature of said second evaporator rises above a predetermined value, and a second control means responsive to the temperature of the refrigerant liquid in said pump, said second control means being adapted and arranged to actuate said refrigerant vapor compressing and condensing apparatus when the temperature of the refrigerant liquid in said pump exceeds a predetermined value.

CARL F. ALSING.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,005,013 Teves June 18, 1935 2,146,797 Dasher Feb. 14, 1939 2,167,036 Baker July 27, 1939 2,426,811 Backstrom Sept. 2 19%? 

